1. Field of the Invention
The present invention relates to a cold preserving container having means for cold accumulation which can preserve the cold in a goods container space of the container.
2. Description of the Prior Art
The conventional cold preserving container has a heat insulating chamber which is formed by a heat insulating box and a door constructed of heat insulating walls. A cold accumulation component enclosing a cold regenerative material is placed in an upper portion of the heat insulating chamber. Goods contained in the goods container space are cooled by the cold air falling down from the cold accumulation component. The cold accumulation component can be removed from the heat insulating chamber and cooled as needed.
Such a conventional container has the advantages that its structure is simple and that the increase of the temperature inside of it can be lowered even where there is no power source. Therefore, the container is convenient where it is to be transported, as by a vehicle. Also, casters are often attached to the container, thereby making it easy to move or transport the container.
However, the conventional cold preserving container, such as the one described above, has the problem that the temperature in the goods container space cannot be controlled.
A cold regenerative material used for a cold accumulation component usually generates cold air having a constant temperature. Therefore, the temperature of the inside atmosphere cooled by the cold air by the cold accumulation component changes with varying outside air temperatures, and it is difficult to maintain the temperature inside of the container at a constant value. Accordingly, for example where the atmosphere or air in the goods container space of the container can be cooled to an adequate temperature in a warm area, the inside air is cooled too much when the container is transported to a cold area, and the contained goods often freeze. In the converse case the goods contained in the container warm and the container often cannot function as a cold preserving container. Particularly, when the contained goods are fresh provisions, the freezing or the warming thereof cannot be allowed.
Moreover, since the cold accumulation component is merely placed in the upper portion of the heat insulating chamber, as on a rack, in the conventional container, it is structurally unstable. This is especially so when the container is transported for long distances, as by a vehicle.